The present invention relates to improvements in sound bars for percussive musical instruments such as xylophones, marimbas and the like.
Musical instruments of the kind to which the present invention relates usually comprise, an array of sound bars disposed in a piano keyboard arrangement and tuned to a corresponding musical scale so that when struck by mallets they will emit tones corresponding to the musical scale. Modification, tuning and/or prolongation of the tonal emissions has been effected, in a variety of ways as described in The Book of the Marimba by Frank K. MacCallum published in 1969 by the Canton Press, N.Y. including, for example, by disposing tuned resonators tubes adjacent each sound bar as described in the U.S. Winterhoff Pat. No. 1,304,435 issued May 20, 1919. While such resonators are effective in the lower octaves, they are not sufficiently effective in the upper portions. The U.S. Roper Pat. No. 4,411,187 discloses control of the decay period of tones emitted by such sound bars in the higher notes as well as the lower, by fabricating such bars of different materials.
A need has existed for a sound bar for such instruments which cannot only produce a desired decay period of the emitted tone but which also can be adapted or adjusted so as to produce one or more of a variety of musical effects, for example, one capable of producing, in addition to a fundamental pitch, other tones such as missing harmonics, or beat frequencies giving a vibrato effect.